An electric motor which cools the inside by using the air taken in as cooling air is known. As this electric motor, an open type electric motor which cools a stator and a rotor by taking the cooling air into the electric motor (for example, refer to JP-A-2001-095204) and a hermetic type electric motor which cools a hermetically-sealed stator and rotor by supplying the cooling air to the outside (for example, refer to JP-A-Hei09-046971) are known.